Rio Tinto, Spain

The Rio Tinto site is ideal for astrobiology research in an extreme acid environment that is a possible analog for the martian subsurface. On both Earth and Mars, water and chemical energy could support (or could have supported) life in an acidic, anoxic environment. Bacteria that are present in the very acidic Rio Tinto play a role in producing acid in the river, a byproduct of the metabolism of iron and sulfur minerals in the region. In addition to the science, a Mars analog drill system was also tested as a prototype for future Mars exploration through the MARTE campaign (Mars Astrobiology Rio Tinto Experiment).